Capturing A Sense of “Mass”

Creative fulfillment aside, one the main reasons I model railroads is that I’m mesmerized by the full size version.   In particular, the sense of overwhelming mass and the stunning horsepower numbers it takes to move just a few cars.  (A GP38-2 tips the scales at 125 tons.)

As I watch YouTube videos such as THIS one (jump to the 1:25 mark), I’m struck by the difference between actual train dynamics and the movement of our plastic models.  Especially knawing to me is the subtle accordion like effect and jerking motion as the model freight cars snap back and forth with the rotation of the model loco’s motor shaft.  It’s subtle but it’s there.  Model trains move like plastic toys not hunks of steel that weigh hundreds of tons.


As the LAJ project moves forward, capturing this sense of mass is high on my list of experiments. To that end, some things that I think will work are:

Layout height:  The closer you can get the models to eye level, the more realistic the viewing experience.  Higher layout heights are a trade off though as they aren’t as easy to work on.  During construction you’ll be standing on a stool quite a bit.  Check

Sound:  The visceral sense of mass isn’t just visual, it’s auditory also.  The deep bass and high fidelity of the headphone system has done wonders.  Check.

Speed curves: Decoder pro makes setting the speed curves a snap.   A few computer key strokes allows you to get a much broader control range for the lower speed ranges the prototype typical runs under.  Check.

Hypderdrive and decoder tuning:  Section 8 of the Tsunami manual reads, “Setting Up the Hyperdrive Tsunami’s Hyperdrive system features high-frequency PWM drive for silent motor control along with load compensation (or back-EMF) to improve low speed operation and maintain constant speed regardless of changes to the motor load. There are four CVs associated with the load compensation feature: CV 10, Back-EMF Cutout CV 209, Kp Coefficient CV 210, Ki Coefficient CV 212, Back-EMF Feedback Intensity”  Friends have told me this tuning makes a huge difference.  I have yet to do this but it’s high on my list.

Trucks:   I’ve always assumed, without thought, that smoother running trucks are better. This is certainly true for over the road freights where you need to pull a lot of cars.  I’m beginning to wonder if trucks that don’t run so freely will give more realistic running qualities during switching.  I don’t know.  It’s a test worth performing.

Car Weight:  What would happen if I grossly overloaded the weight of my freight cars?  How would that change their dynamics?  It’s worth testing.  I’m not sure how practical this would be though for cars that would be difficult to add weight to such as tanks, gons, flats, etc.


To be continued…..